Saute onion in hot oil in a medium saucepan over medium heat until tender. Add garlic and ginger; cook, stirring constantly for about a minute or until fragrant. Add ketchup and peach syrup. Reduce the heat to low and simmer for about 30 minutes until sauce thickens - stirring occasionally. Add vinegar and salt and pepper to taste.
Use half of the peach mixture as a marinade for your favorite meat. Baste with remaining peach mixture.
